El Niño Modoki is a coupled ocean-atmosphere phenomenon in the tropical Pacific.
It is different from another coupled phenomenon in the tropical Pacific namely, El Niño.
Conventional El Niño is characterized by strong anomalous warming
in the eastern equatorial Pacific (see figure below).
Whereas, El Niño Modoki is associated with strong anomalous warming in the central tropical Pacific
and cooling in the eastern and western tropical Pacific (see figure below).
Associated with this distinct warming and cooling patterns the teleconnections are very different
from teleconnection patterns of the conventional El Niño.
Hence, the new phenomenon is of interest to the climate community.

Anomalous SST during
El Niño

Anomalous SST during
El Niño Modoki

The name
"
El Niño Modoki
"
was first coined by
Prof. Yamagata
in various press releases. Researchers of the Climate Variations Research Program of Frontier Research Center for Global Change (FRCGC) lead by Prof. Yamagata documented this phenomenon for the first time. This phenomenon appears as second dominant mode of interannual variability in the tropical Pacific:

First EOF mode of SSTA representing
El Niño

Second EOF mode of SSTA representing
El Niño Modoki

El Niño Modoki Impacts

The El Niño Modoki phenomenon is characterized by the anomalously warm
central equatorial Pacific flanked by anomalously cool regions in both west and east.
Such zonal SST gradients result in anomalous two-cell Walker Circulation
over the tropical Pacific, with a wet region in the central Pacific.